In the endothelium very little is known about the mechanisms that are involved in regulating cellular signaling via gap junctions in response to hemodynamic shearing forces. Relatively few studies have investigated the expression and function of individual gap junction proteins in response to flow-induced fluid shear stress. Although nitric oxide (NO) has been shown to modulate the gap junction communication in static cell culture, the regulation of shear induced NO on this communication has not yet been explored. The question of how this autacoid release regulates different connexins in the various hemodynamic schemes (laminar or disturbed) needs to be investigated. In addition, the question of how fluid shear stress affects intercellular communication in the absence of cytoskeleton also needs to be studied, since cytoskeletal proteins are speculated to be involved in gap junction assembly. The strategy outlined in this proposal will allow us to elucidate the poorly understood physiological regulatory mechanisms of gap junctions in the endothelium during vessel wall remodeling in response to various hemodynamic shearing forces using newly developed techniques such as siRNA and Long Oligo microarrays.